Solid oxide fuel cell interconnect cells

Abstract

A bonding layer, disposed between an interconnect layer and an electrode layer of a solid oxide fuel cell article, may be formed from a yttria stabilized zirconia (YSZ) powder having a monomodal particle size distribution (PSD) with a d 50 that is greater than about 1 μm and a d 90 that is greater than about 2 μm.

What is claimed is: 
     
         1 . An interconnect cell of a solid oxide fuel cell stack, the interconnect cell comprising:
 an interconnect layer;   a first bonding layer including yttria stabilized zirconia and having a thickness of not greater than 100 μm; and   a second bonding layer including yttria stabilized zirconia and having a thickness of not greater than 100 μm,   wherein the interconnect cell is configured to reach a Steady State Area Specific Resistance within a time period of not less than 600 hours of operation.   
     
     
         2 . The interconnect cell of  claim 1 , wherein the area specific resistance of the interconnect cell is configured to reach the Steady State Area Specific Resistance within a time period of not less than 800 hours. 
     
     
         3 . The interconnect cell of  claim 1 , wherein the area specific resistance of the interconnect cell is configured to reach the Steady State Area Specific Resistance within a time period of not less than 1000 hours. 
     
     
         4 . The interconnect cell of  claim 1 , wherein the first bonding layer has an average thickness of not less than 5 μm. 
     
     
         5 . The interconnect cell of  claim 1 , wherein the second bonding layer has an average thickness of not less than 5 μm. 
     
     
         6 . The interconnect cell of  claim 1 , wherein the area specific resistance of the interconnect cell is not greater than 0.20 ohm cm 2  after a time period of 3000 hours. 
     
     
         7 . The interconnect cell of  claim 1 , wherein the interconnect layer includes niobium doped lanthanum strontium titanate material. 
     
     
         8 . The interconnect cell of  claim 1 , wherein the interconnect layer has an average thickness of not less than about 5 μm to not greater than about 100 μm. 
     
     
         9 . The interconnect cell of  claim 1 , wherein the first bonding layer is a cathode bonding layer disposed between the interconnect layer and a cathode of the solid oxide fuel cell stack, wherein the cathode bonding layer further includes a lanthanum strontium manganite material. 
     
     
         10 . The interconnect cell of  claim 1 , wherein the second bonding layer is an anode bonding layer disposed between the interconnect layer and an anode of the solid oxide fuel cell stack, wherein the anode bonding layer further includes nickel, nickel oxide, or a combination thereof. 
     
     
         11 . A solid oxide fuel cell stack, comprising:
 a first electrode layer;   a first electrolyte layer overlying the first electrode layer;   a second electrode layer overlying the first electrolyte layer;   an interconnect cell disposed between the second electrode layer and a third electrode layer of the solid oxide fuel cell stack, the interconnect cell comprising:   an interconnect layer;   a first bonding layer disposed between the interconnect layer and the second electrode layer, wherein the first bonding layer includes yttria stabilized zirconia and has an average thickness of no less than 5 μm to not greater than 100 μm; and   a second bonding layer disposed between the interconnect layer and the third electrode layer, wherein the second bonding layer includes yttria stabilized zirconia and has an average thickness of no less than 5 μm to not greater than 100 μm,   wherein the interconnect cell is configured to reach a Steady State Area Specific Resistance within a time period of not less than about 800 hours of operation;   a second electrolyte layer overlying the third electrode layer; and   a fourth electrode layer overlying the second electrolyte layer.   
     
     
         12 . The solid oxide fuel cell stack of  claim 11 , wherein the first bonding layer has a porosity of not less than 5 vol % to not greater than 60 vol %. 
     
     
         13 . The solid oxide fuel cell stack of  claim 11 , wherein the second bonding layer has a porosity of not less than 5 vol % to not greater than 60 vol %. 
     
     
         14 . The solid oxide fuel cell stack of  claim 11 , wherein the interconnect cell is configured to reach a Steady State Area Specific Resistance within a time period of not less than about 1000 hours. 
     
     
         15 . The solid oxide fuel cell stack of  claim 14 , wherein the area specific resistance of the interconnect cell is not greater than about 0.20 ohm·cm 2  after a time period of about 3000 hours. 
     
     
         16 . A method comprising operating an interconnect cell such that the interconnect cell reaches a Steady State Area Specific Resistance within a time period of not less than 600 hours, wherein the interconnect cell comprise:
 an interconnect layer;   a first bonding layer including yttria stabilized zirconia and having a thickness of not greater than 100 μm; and   a second bonding layer including yttria stabilized zirconia and having a thickness of not greater than 100 μm.   
     
     
         17 . The method of  claim 16 , wherein the time period is not less than 800 hours, and the interconnect cell reaches the Steady State Area Specific Resistance within the time period of 800 hours. 
     
     
         18 . The method of  claim 16 , wherein the time period is not less than 1000 hours, and the interconnect cell reaches a Steady State Area Specific Resistance within the time period of 1000 hours. 
     
     
         19 . The method of  claim 16 , wherein the time period is not less than 1200 hours, and the interconnect cell reaches a Steady State Area Specific Resistance within the time period of 1200 hours. 
     
     
         20 . The method of  claim 16 , wherein the interconnect cell reaches the area specific resistance of not greater than 0.16 ohm·cm 2  after keeping in heat for a time period of 3000 hours.